I with this circuit -- 2 resistors and 2 sources....

AI Thread Summary
The discussion revolves around solving a circuit problem involving two resistors and two sources, with a focus on finding the output voltage (v0) and output current (i0). The user initially struggles with their equation and the expected answers of 20V and 10A, leading to confusion over the correct circuit diagram. Clarification reveals discrepancies between two images provided, with one being confirmed as the correct reference. The conversation highlights the importance of correctly interpreting current labels in the circuit, suggesting that a potential typo may have caused the user's misunderstanding. Ultimately, the correct relationship between the voltages and currents in the circuit is emphasized.
edgarpokemon
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Homework Statement


The problem is in this link

https://www.chegg.com/homework-help/find-vo-io-circuit-fig-226figure-226-chapter-2-problem-7pp-solution-9780078028229-exc
upload_2018-1-24_9-50-4.png


Homework Equations



3. The Attempt at a Solution
[/B]
15=[io/3]+[io/3]+ [vo/12]

I got this equation for the problem. Since the voltages of both resistors are in parallel, the both are equal. So for the first resistor from left to right... v1=[2/3]io but also v1=v0. So i replace vo with v1 in my equation, but i don't get the answers that i am suppose to get, which are 20V and 10 amps. It asks to find v0 and i0. I asked in other website and both said they did nkt get 20 or 10 neither. Help!
 

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Did you notice that the two pictures you linked are different? The top picture has i0/3 in the 2 Ohm resistor and the bottom picture has i0. Which is the correct problem?
 
phyzguy said:
Did you notice that the two pictures you linked are different? The top picture has i0/3 in the 2 Ohm resistor and the bottom picture has i0. Which is the correct problem?

Oh sorry, the first problem from the top is the correct one. The one in color
 
edgarpokemon said:
Oh sorry, the first problem from the top is the correct one. The one in color

Are you sure? The lower one is consistent with your 10Amp/20V answer. The upper one is not.
 
phyzguy said:
Are you sure? The lower one is consistent with your 10Amp/20V answer. The upper one is not.

Yes i am sure, the one in color is the one that i have on my book. I already spent 3 4 hours on that problem because i can't get those answers so i am sure that's the one haha
 
edgarpokemon said:
Yes i am sure, the one in color is the one that i have on my book. I already spent 3 4 hours on that problem because i can't get those answers so i am sure that's the one haha

Well, the answer to the one in color is most definitely not 10 A / 20 V.
 
phyzguy said:
Well, the answer to the one in color is most definitely not 10 A / 20 V.
Thank you. So is the equation that i got correct? Is vo also equal to 2io/12?
 
edgarpokemon said:
Thank you. So is the equation that i got correct? Is vo also equal to 2io/12?

No. Since the 2 Ohm resistor and the 12 Ohm resistor are in parallel, they have the same potential (v0) across them. So if the 2 Ohm resistor has a potential of v0 across it, and a current of i0/3 is flowing through it, then by Ohm's law v0 = 2*i0/3. How did you get v0 = 2*i0/12?
 
I strongly suspect that the ##\frac{i_o}{3}## current label on the ##2 \;\Omega## resistor is a typo. Pretty sure it would make more sense if it was just ##i_o##.
 
  • #10
gneill said:
I strongly suspect that the ##\frac{i_o}{3}## current label on the ##2 \;\Omega## resistor is a typo. Pretty sure it would make more sense if it was just ##i_o##.
Thank you!
 
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